Atlanta leads the nation in attracting the labor market's most coveted demographic: college-educated workers ages 25 to 34. Among the key reasons is that housing costs have stayed dramatically lower here than in inflated coastal markets like Boston, Los Angeles, San Francisco, and Seattle. Katrina spillover has brought other transplants, helping to seed new jobs and businesses. Ironically, while traditional pillars like Delta Air Lines and BellSouth are starting to sag, small and medium size businesses are picking up the slack. One driver: Midtown Mile, a 14-block complex, opens its first phase next year with dozens of new hotels, shops, and offices. Another is Technology Enterprise Park, a bioscience research center. "Most of the growth is coming from small firms that hire a dozen workers," says Rajeev Dhawan, director of Georgia State University's Economic Forecasting Center.